scholarly journals Compendium of Low-Cost Pacific Salmon and Steelhead Trout Production Facilities and Practices in the Pacific Northwest.

1984 ◽  
Author(s):  
Harry G. Senn
Keyword(s):  
Pacific Northwest ◽  
Pacific Salmon ◽  
Low Cost ◽  
Steelhead Trout ◽  
The Pacific ◽  
Production Facilities

Detecting persistent change in the habitat of salmon-bearing streams in the Pacific Northwest

2004 ◽  
Vol 61 (2) ◽  
pp. 283-291 ◽  
Author(s):  
David P Larsen ◽  
Philip R Kaufmann ◽  
Thomas M Kincaid ◽  
N Scott Urquhart
Keyword(s):  
Pacific Northwest ◽  
Pacific Salmon ◽  
Monitoring Network ◽  
Habitat Characteristics ◽  
Detection Sensitivity ◽  
Trend Detection ◽  
Spatial And Temporal Variation ◽  
The Pacific ◽  
Two Factors ◽  
Consistent Change

In the northwestern United States, there is considerable interest in the recovery of Pacific salmon (Oncorhynchus spp.) populations listed as threatened or endangered. A critical component of any salmon recovery effort is the improvement of stream habitat that supports various life stages. Two factors in concert control our ability to detect consistent change in habitat conditions that could result from significant expenditures on habitat improvement: the magnitude of spatial and temporal variation and the design of the monitoring network. We summarize the important components of variation that affect trend detection and explain how well-designed networks of 30–50 sites monitored consistently over years can detect underlying changes of 1–2% per year in a variety of key habitat characteristics within 10–20 years, or sooner, if such trends are present. We emphasize the importance of the duration of surveys for trend detection sensitivity because the power to detect trends improves substantially with the passage of years.

The Rationality of Mechanization in the Pacific Salmon-Canning Industry before the Second World War

1988 ◽  
Vol 62 (4) ◽  
pp. 626-655 ◽  
Author(s):  
Dianne Newell
Keyword(s):  
Pacific Northwest ◽  
Pacific Salmon ◽  
New Technology ◽  
Continuous Process ◽  
Second World War ◽  
Process Technology ◽  
The Pacific ◽  
Labor System ◽  
Canning Industry ◽  
Second World

An industry may fail to adopt or to extend new technology for many reasons other than lack of entrepreneurial vision. In the following article, Professor Newell considers the halting and incomplete diffusion of mechanization and continuous-process technology in the salmon-canning industry of the Pacific Northwest. She shows that the fragile and cyclical character of the natural resource, the labor system employed, and the remote and isolated locations of individual production units all affected cannery operators' decisions about technology adoption, and that the persistence of manual labor reflected rational, not reactionary, business choices.

scholarly journals Pathogens of Pacific Lamprey Detected Through Routine Fish Health Screenings

2019 ◽  
Vol 10 (2) ◽  
pp. 517-524 ◽  
Author(s):  
Jeffrey C. Jolley ◽  
Kenneth M. Lujan
Keyword(s):  
Pacific Northwest ◽  
Aeromonas Hydrophila ◽  
Vibrio Vulnificus ◽  
Conservation Management ◽  
Pacific Salmon ◽  
Specific Information ◽  
Fish Health ◽  
Fish Pathogens ◽  
Pacific Lamprey ◽  
The Pacific

Abstract Interest in conservation, management, and captive rearing of Pacific Lamprey Entosphenus tridentatus in the Pacific Northwest has risen in recent years. General and specific information regarding the occurrence of fish pathogens and the risk of Pacific Lamprey as a vector for pathogens to other species is not well understood. Specific efforts to captively rear or artificially propagate Pacific Lamprey at facilities that are used for Pacific salmon Oncorhynchus spp. have increased. We performed fish health surveys on wild-caught larval and adult Pacific Lamprey from locations that were used as lamprey sources for captive research to determine the occurrence of bacteria, viruses, and parasites that may be pathogens. A variety of potential pathogens was detected, most notably Aeromonas hydrophila and Vibrio vulnificus from larval Pacific Lamprey and A. salmonicida from adult lampreys. There was a general lack of pathogenic activity and absence of viral detections from all lampreys. The diversity of bacteria encountered from the larvae in our study could be indicative of the wide diversity of bacteria that is known to be associated with larval lamprey in general. Further efforts to understand pathogenic risk from Pacific Lamprey to salmonid propagation programs are warranted.

scholarly journals Rapid Quantitative Assessment of Rhizoctonia Resistance in Roots of Selected Wheat and Barley Genotypes

Plant Disease ◽  
2016 ◽  
Vol 100 (3) ◽  
pp. 640-644
Author(s):  
Patricia A. Okubara ◽  
Natalie Leston ◽  
Ute Micknass ◽  
Karl-Heinz Kogel ◽  
Jafargholi Imani
Keyword(s):  
Pacific Northwest ◽  
Management Practices ◽  
Production Systems ◽  
Low Cost ◽  
Genetic Resistance ◽  
Bare Patch ◽  
Rhizoctonia Root Rot ◽  
The Pacific ◽  
Wide Range ◽  
Barley Genotypes

Rhizoctonia solani AG8, causal agent of Rhizoctonia root rot and bare patch in dryland cereal production systems of the Pacific Northwest United States and Australia, reduces yields in a wide range of crops. Disease is not consistently controlled by available management practices, so genetic resistance would be a desirable resource for growers. In this report, we describe three rapid and low-cost assays for R. solani AG8 resistance in wheat and barley, with the view of facilitating screens for genetic resistance in these hosts. The first assay uses 50-ml conical centrifuge tubes containing soil infested with R. solani AG8 on a substrate of ground oats. The second assay uses roots of 3-day-old seedlings directly coated with infested ground oats, followed by incubation in plastic dishes. The third assay, suitable for barley, uses whole infested oat kernels in 50-ml tubes. Symptoms are quantified on the bases of root fresh weight and total root length at 7 and 3 days for the tube and coating assays, respectively. Each of the assays show the same disease differential between susceptible and partially resistant wheat genotypes. The assays can be conducted in the laboratory, growth chamber, or greenhouse.

Influence of landscape on resident and anadromous life history types of Oncorhynchus mykiss

2008 ◽  
Vol 65 (6) ◽  
pp. 1013-1023 ◽  
Author(s):  
Shawn R. Narum ◽  
Joseph S. Zendt ◽  
David Graves ◽  
William R. Sharp
Keyword(s):  
Life History ◽  
Oncorhynchus Mykiss ◽  
Pacific Northwest ◽  
Isolation By Distance ◽  
High Elevation ◽  
Steelhead Trout ◽  
Mantel Tests ◽  
Lower Elevation ◽  
The Pacific ◽  
High Gradients

Landscape features can significantly influence genetic and life history diversity of rainbow/steelhead trout, Oncorhynchus mykiss . In this study, heterozygosity of 21 populations of O. mykiss from the Pacific Northwest, USA, was significantly negatively correlated with features such as elevation (P = 0.0023), upstream distance (P = 0.0129), and precipitation (P = 0.0331), and positively correlated with temperature (P = 0.0123). Mantel tests of isolation by distance were significant for anadromous populations (P = 0.007) but not for resident collections (P = 0.061), and suggested that fluvial distance was not the only significant physical variable that influenced genetic structure of life history types. Principal components interpolated to the drainage indicated that high-elevation sites were primarily occupied by the resident form, and high gradients and barriers act to limit anadromous distribution to lower elevation sites. These patterns of O. mykiss life history diversity provide insight regarding the interaction, distribution, and limitations of resident and anadromous forms of the species within this region.

Do bears facilitate transfer of salmon resources to aquatic macroinvertebrates?

2005 ◽  
Vol 62 (10) ◽  
pp. 2285-2293 ◽  
Author(s):  
Monika Winder ◽  
Daniel E Schindler ◽  
Jonathan W Moore ◽  
Susan P Johnson ◽  
Wendy J Palen
Keyword(s):  
Pacific Northwest ◽  
Life Histories ◽  
Pacific Salmon ◽  
Stream Invertebrates ◽  
The Pacific ◽  
Salmon Carcass ◽  
Isotope Analyses ◽  
Long Term Survey ◽  
Spawning Habitats

In coastal areas of the Pacific Northwest bears (Ursus spp.) prey heavily on spawning Pacific salmon (Oncorhynchus spp.) and selectively kill energy-rich individuals that are the most recent arrivals on spawning grounds. Pacific salmon eventually die in spawning habitats anyway, albeit with considerably lower energetic content. We investigated whether foraging activities of bears facilitate growth of stream invertebrates by increasing the duration of salmon carcass availability and the nutritional value of carcasses for scavengers. Our survey in southwest Alaska showed that carcasses are highly colonized by caddisfly (Trichoptera) larvae. Caddisflies show a strong preference for bear-killed over senescent carcasses, which may be a result of extended temporal availability, improved accessibility of consumable tissue, and higher energetic content of bear-killed fish. Isotope analyses further indicate uptake of marine-derived nutrients in caddisflies during the salmon run, which, however, does not extend into subsequent generations. Thus, species with life histories linked to the annual marine derived nutrient pulse gain the biggest advantage from the salmon resource subsidy. A long-term survey in several creeks in this region showed that bear predation intensity varied greatly among creeks and years, therefore indirect effects of bear predation on aquatic scavengers are likely highly patchy in time and space.

scholarly journals Hop Powdery Mildew Control Through Alteration of Spring Pruning Practices

Plant Disease ◽  
2016 ◽  
Vol 100 (8) ◽  
pp. 1599-1605 ◽  
Author(s):  
Claudia Probst ◽  
Mark E. Nelson ◽  
Gary G. Grove ◽  
Megan C. Twomey ◽  
David H. Gent
Keyword(s):  
Powdery Mildew ◽  
Pacific Northwest ◽  
Low Cost ◽  
Specific Effect ◽  
Disease Development ◽  
Quality Factors ◽  
Early Season ◽  
Yield And Quality ◽  
The Pacific ◽  
Podosphaera Macularis

Podosphaera macularis, the causal agent of hop powdery mildew, is a recurrent threat to hops in the Pacific Northwest because of the potential to reduce cone yield and quality. Early-season pruning is a common practice in hop production for horticultural reasons. Studies were conducted over a 3-year period in a commercial hop yard to quantify the effect of pruning method and timing on disease development, yield, and cone quality factors. A 4-week delay in pruning reduced the incidence of leaves with powdery mildew from 46 to 10% and cones from 9 to 1%, with the specific effect being season dependent. Pruning using chemical desiccants rather than by mechanical means had similar effects on disease levels on leaves. On cones, though, chemical pruning had a small but significant reduction in the incidence of powdery mildew compared with mechanical pruning. Cone yield, levels of bittering-acids, and color were not negatively affected in any individual year or cumulatively over three seasons when pruning treatments were applied repeatedly to the same plots during the study period. Delayed pruning may offer a low-cost means of reducing both the incidence of powdery mildew and early-season fungicide inputs in certain cultivars.

scholarly journals Rapid discovery of SNPs that differentiate hatchery steelhead trout from ESA-listed natural-origin steelhead trout using a 57K SNP array

2018 ◽  
Vol 75 (7) ◽  
pp. 1160-1168 ◽  
Author(s):  
Wesley A. Larson ◽  
Yniv Palti ◽  
Gunagtu Gao ◽  
Kenneth I. Warheit ◽  
James E. Seeb
Keyword(s):  
Pacific Northwest ◽  
Puget Sound ◽  
Snp Array ◽  
Habitat Destruction ◽  
Steelhead Trout ◽  
Conservation Genomics ◽  
Natural Origin ◽  
Polymorphic Snps ◽  
The Pacific ◽  
Outlier Tests

Natural-origin steelhead trout (Oncorhynchus mykiss (Walbaum, 1792)) in the Pacific Northwest, USA, are threatened by a number of factors including habitat destruction, disease, decline in marine survival, and a potential erosion of genetic viability due to introgression from hatchery strains. Our major goal was to use a recently developed SNP array containing ∼57 000 SNPs to identify a subset of SNPs that differentiate hatchery and natural-origin populations. We analyzed 35 765 polymorphic SNPs in nine populations of steelhead trout sampled from Puget Sound, Washington, USA. We then conducted two outlier tests and found 360 loci that were candidates for divergent selection between hatchery and natural-origin populations (mean FCT = 0.29, maximum = 0.65) and 595 SNPs that were candidates for selection among natural-origin populations (mean FST = 0.25, maximum = 0.51). Comparisons with a linkage map revealed that two chromosomes (Omy05 and Omy25) contained significantly more outliers than other chromosomes, suggesting that regions on Omy05 and Omy25 may be of adaptive significance. Our results highlight several advantages of the 57 000 SNP array as a tool for population and conservation genomics studies.

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